Automatic feed for punch presses



March 17 1931.

J. WITTEK AUTOMATIC FEED FOR PUNCH PRESSES Filed Aug. 29, 1927 2 Sheets-Sheet 2 z fltfarzzg Patented Mar. 17. 1931 UNITED STATES vJOSEPH WTTTEK; OF CHI ECAGO, ILLINOIS AUTOMATIC FEED FOR PUNCH PRESSES Application filed August 29, 1927. Serial No. 216,027.

This invention relates generally to improvements in a combination die set and feed for punch presses and the like, and has among its objects to provide a new and useful automatic '5 .feed for rapidly superseding hand feeding.

Another object of the invention is found in the provision of flexible and adjustable drive vfrom the. fly-wheel crank shaft of a punch press to the automatic feed.

A further object of my invention resides in the provision of driving or propelling means for the automatic feed which may be adjusted to intermittently feed material or stock at varying lengths and speed into the ress.

A still further object of the invention embodies the provision of a pair of friction rolls and drivemechanism for same and means for separating said rolls to release their frictional grip of the stock or material.

Another object of the invention is found in the provision of a releasable friction clamp for retaining the stock when the rolls are separated to keep same from'slipping backward or forward and also for straightening the stock as it is fed from a coil into the die set.

It isalso an object of the invention to provide novel features of construction and arrangement of the parts and members of a device of this character tending'to enhance the efficiency thereof. a

fWVith the above and other objects inview, my invention consists in the novel combination, construction and arrangement of the parts and members shown in one embodiment in the attached drawings, described in the following specifications, and particularly pointed out'in the appended claims.

Referring to the illustrations:

40 Figure 1 is an end elevation of a punch press embodying my invention;

Figure 2 is a side elevation of-a die set and the improved feed;

Figure 3 is a planview of the feed taken on line 33 of Figure 2;

Figure 4 is an end elevation of the feed- Referring now to theseveral illustrations,

co-operate with the lower or female die 18 l which is rigidly mounted to the upper face of the die shoe 16.

In its vertical reciprocation, the punch holder 14 is positively guided in its relative movement to the die shoe 16 by'means of the leader pins'19 which are secured rigidly to the die shoe 16 and adapted for sliding movement into the bushings 20 rigidly held in the punch holder 14:.

. It may be noted here that the bushings 20 are provided with an annular oil groove 20 from which extends a passage 2O for oiling of the leader pin 19. The punch holder 14 is provided with an oil hole 146* leading into'the annular oil chamber 20 The die shoe 16 is provided at the feed inlet end with a pair of integral end extensions 16 for support of'the shaft 21 upon which-is rigidly mounted the feed roll 21.

A co-operating feed roll 22 rigidly mounted on shaft 22 is rotatably supported, in the bearings 22 Thebearings 22 are loosely mounted in the extensions 16.

A air of gears 23 rigidly mounted on shafts 21 and 22 afford means for of transmitting rotary motion from shaft 21 to shaft 22*. A washer 22 fixed to shaft 22 together with the gear .23 thereon retain the shaft '22 against longitudinal shifting in its support.

To maintain the upper roll 22in frictional contact with the lower roll 21, coil springs 24 are provided the lower end of which rest upon the bearings 22 and the upper end of which abut against washers 25 which are held against the top of the coil springs by adjustment screws 26 mounted in the top of the removable caps 27. The caps 27 are screw mounted to the top of the extensions 16 and provide a housing for the coil springs 24.

To'aifordtransmission of power from the sprocket 13 to the rolls 21 and 22, a shaft 28 is journaled in the die shoe at 28*. A removably mounted sprocket 29 is fixed to one end of the shaft 28 and a removably mounted sprocket chain 30 transmits power from the sprocket 13 to the sprocket 29.

Since the sprockets 13 and 29 are remov: able, they may readily be changed to vary the speed of the die mechanism and thus cause a more rapid or slower movement of the stock 33 through the die set.

A suitable idler sheave 41, adjustably mounted onthe post 42 is provided as a tightener for the chain drive 30.

A bevel pinion 31 rigidly mounted on the opposite end of shaft 28 meshes with the bevel gear 32 which is rigidly fixed to the roll shaft 21. It is now apparent that rotary power from the crank shaft 12 is readily applied to the rolls 21 and 22 through the intermeshing gears 23.

To provide guiding means for the material 33 which is to be fed by the friction rolls 21 and 22, a pair of collars 34 having depending integral fingers is mounted upon the shaft 35 which is fixed in the casting 36. The casting 36 is formed with a pair of end portions which are mounted to the extensions 16 by means of screws 36. The end portions of the casting 36 are interconnected with a cross bar portion 36 formed integrally therewith and the entire casting being adjustable vertically by virtue of the slotted holes 36 upon the extensions 16 so as to bring the top of the bar portion 36 beneath the material or stock 33. It may be noted that the guide collars are provided with set screws to retain them in fixed position upon setting to the sides of the stock 33.

A frictional clamp comprising a bar 38 is provided to engage upon the upper face of the material or stock '33 to thus frictionally retain the stock 33 between it and the bar portion 36 during the punching operation of the press when the rolls are separated as will be more fully hereinafter disclosed.

The bar 38 is provided with a pair of spaced stud bolts 39 which are rigidly mounted in the bar 38-and which extend siidably through a pair of ears 36 A coil spring 40 mounted on each stud bolt 39 between the ings 22 in a manner to be lifted by the arm 43 upon engagement by the end of the screw 44 which is carried in the punch holder 14.

It will now be readily apparent that the rolls 21 and 22 by virtue of the pressure of the coil springs 24 and the interconnecting drive mechanism, will continue to feed a strip of material or stock 33 over the die 18 and beneath its cover plate 18 until released by the spreading of the rolls or until the stock 33 engages the stop 16? which prevents further movement of the stock 33. The rolls in this instance may continue to rotate,'but they will not be able to propel the stock further. When the operator presses down upon the foot treadle to place the press 10 into operation, the punch holder 14 will be reciprocated to bring the die 15 into operative engagement with the die 18 to simultaneously punch the material, in this instance, a round die punch 15 and, a square die punch 15 and a shear 15 At a certain instant, during the downward movement of the die 15 and just before the actual engagement of the die 15 with the stock 33, the end of the roller releasing screw 44 will engage the arm 43 to'thus lift the upper roller 22 on its supports against the pressure of the springs 24, thereby releasing the rol s from frictional contact with the stock 33. i

j The length of the screw 44 beneath the punch holder 14 may be varied to so regulate the interval 'of time during which the rolls will be released from the stock 33 to permit the die 15 to pass through the stock 33 and withdraw therefrom. Likewise the length of the material fed to the die or press plunger .may be controlled by the adjustment of screw 44.

Upon the shearing operation of the shear 15, the stock 33 will then be readily moved forward to engage with the stop 16 as the arm 43 will be released long before the die 15 reaches its uppermost position and the springs 24 will'be permitted to bring the up per roll 22 again into frictional contact with the stock 33 to shift it against the stop 16 when the next punching operation will be performed.

The illustrations show a die set for punching a product comprising substantially a square piece of material with a hole in the center thereof. The finished product being punched through the die 18 and shoe 16 into a chute 47 and thescrap material passing into the chutes 46 and 48. r

In starting the operation of the feed above described, the stock or band of material is first passed between the spring-pressed bar 38 and the bar portion 36 which is readily done by lifting the projecting portion of the bar 38 against the pressure of the springs 40 to permit the insertion of the band of material thereunder. The stock 33 is then inserted between the rolls-21 and 22. This also is readily done by pressing down on the lifting arm 43 to thereby raise its opposite end which lifts the bearing 22 and the upper roll 22. If it is desired to hold the roll 22 in raised position, the pin 49 which is attached with a chain 50 to the arm 43 may readily be inserted into the. hole 51 in extension 16 underneath the raisedend of the arm 43. lVhen the arm 43 is released, the pin 49 will continue to hold theraised arm 43 and the roll 22 in raised position.

After the stock 33 is passed through the rolls it is then inserted under the die plate 18 and pulled to the stop 16 then the guide collars 34 may be adjusted to the sides of the stock 33 and permanently set by tightening of their set screws. withdrawn to allow the rolls to frictionally engage the stock 33 and the press may then be set into operation.

WVhile I have preferably shown and described my invention as applicable to a punch press equipped with dies for performing a punching and shearing operation on the Inaterial fed by my improved mechanism, it

- will be readily apparent that the reciprocating plunger of the press may be obviously ing punch holder, a set of dies carried by said die set, a pair of operatively interconnected rolls mounted on an extension of said die shoe, resilient means for retaining said rolls in contact with each other, means for imparting continuous rotary motion during the opera.- tion of the press to said rolls from said shaft on said press, saidrolls adapted to receive a strip of material between them and frictionally feed said material to said die set, and means arranged for lifting the upper roll away from lower roll for arresting the movement of said material in said die set during the continuous rotationof said rolls and during their continued operative interconnection.

In combination with a punch press having a fly wheel shaft, an automatic feed comprising a set of dies operatively connected to mounted adjacent said set of dies, resilient means exerting pressure against one of said rolls for retaining said rolls in contact with each other, a roll operating shaft mounted adjacent said dies, a sprocket on one end of said roll operating shaft, a sprocket on said fly wheel shaft, a chain drive connecting said sprockets, means for positively rotating The pin 49 may then be both of said rolls operatively connected to the other end of said roll operating shaft, and

means for vertically displacing one end of one of said rolls for arresting the movement of the materialthrough said dies during the con tinuous rotation of said rolls. 3. A feed mechanism for intermittentl feeding a strip of material, comprising a lower feed roll, an upper companion feed roll,

means for operatively interconnecting and continuously revolving said rolls in relative opposite directions, resilient means for pressing said rolls toward each other, whereby material introduced between said rolls will be advancedby engagement thereof by said rolls, and intermittently operable means adapted for exerting pressure against said resilient means to thereby remove the pressure of said rolls on said material to arrest the movement of the material during the continuous opera-' tive interconnection of said rolls and to continue the movement of the material upon the rolls of said intermittently operable means.

4. The combination with a reciprocating plunger, of an automatic feed mechanism comprising a pair of rolls adapted for continuous rotation during the operation of said plunger, resilient means for retaining said rolls in positive frictional contact for frictionally feeding a strip of material to said plunger, means for arresting the movement of said material just before the operation of 7 said plunger thereon and during the uninter rupted rotation of both of said rolls, a sprocket on said feed mechanism, means imparting rotary motion from said sprocket .to

said rolls, a second sprocket onthe flywheel shaft of said press, and a chain drive connecting said sprockets for imparting power to a said feed mechanism from said flywheel shaft.

5. The combination with a reciprocating plunger, of .an automatic feed mechanism comprising a pair of rolls adapted for continuous rotation during the reciprocation of said plunger, resilient means for retaining said rolls in positive frictional contact for frictionally engaging a strip of material to feed same to said plunger for operation thereon, means for controlling the length of said material fed to said plunger by arresting the movement thereof during the uninterrupted rotation of both of said rolls, said means including the release of said rolls from frictional contact with said material during the continuous rotation of both of said rolls,

and means for imparting rotary motion to said press, said feed comprising a pair of rolls said rolls from the flywheel shaftjof said plunger. 1

6. An automatic feed mechanism adapted 'for attachment to a press having a reciprocatlengths, means for limiting and arresting the movement of said material during the uninterrupted rotation of said rolls, said means intermittently spreading said rolls apart to release said material from propulsion by said rolls during the continuous rotation'of said rolls, a plurality of resilient members for returning said rolls into frictional contact With said material upon the release of said roll spreading means, and means for imparting rotary motion to said rolls from the operating mechanism of saidpress.

7. An automatic feed mechanism comprising a pair of rolls adapted for continuous rotation and adapted to frictionally engage a strip of material between them and feed same to'a machine for operation thereon, resilient means for affecting the frictional contact of said rolls with said material, means for intermittently spreading said rolls apart against the pressure of said resilient means to release said material from propulsion bysaid rolls during the operation thereon of said machine,

a pair of gears operatively interconnecting said rolls whereby. said rolls are continuously rotated during their propulsion of the material and during their-release of propulsion of the material, and means for transmitting power from said machine to said rolls.

In Witness whereof I aflix my signature.

JOSEPH NVITTEK. 

